1. Field of the Invention
The present invention relates to an elastic wave device that includes a piezoelectric material layer and an interdigital transducer (IDT) electrode thereon.
2. Description of the Related Art
Various elastic wave devices are known that have an IDT electrode formed by stacked metal films. For example, the elastic wave device described in Japanese Unexamined Patent Application Publication No. 2012-175315 includes a piezoelectric substrate and an IDT electrode thereon. This IDT electrode has a structure in which NiCr, Pt, Ti, and AlCu films are stacked from the piezoelectric substrate side. The Ti film prevents atomic diffusion between the Pt and AlCu films.
This Ti film is not a sufficiently effective diffusion barrier when polycrystalline.